Boom type excavator



Dec. 3, 1940- c. GEORGE BOOM TYPE EXCAVATOR Filed June 22, 1939 2 Sheets-Sheet l awe/WM Char/6s L. Geo/f6 Dec. 3, 1940. c. 1.. GEORGE BOOM TYPE EXCAVATOR Filed June 22, 1959 2 Sheets-Sheet 2 3mm Char/es L. Geo/ye ba /an Patented Dec. 3, 1940 r UNITED." STATES PATENT! OFFICE j f 2,223,608". Boom TYPE Exc vA'r-oa x Charles L. George, Findlay, Ohio-,fassignorto The 1 ,Buckeye Traction Ditcher Company," Findlay,

- Ohio,acorporationofhio j c f ppumnon June '22, 1939, Serial No. 280,474 4 Claims. (01.37 189) This invention relates to excavators or trenchers, but more particularly to boom-type trenchers,- in which aseries of buckets operate to excavate and on opposite sides of which is an auxil- 5 iary digger for enlarging the width of the cut.

Anobject is to produce; an auxiliary digger of the above type, the cutters of'which are arranged to operate, in close: succession and not at relati-vely widely spaced intervals, as in the case,v for example, where the successively operating cutters are spaced ninety degrees from each other.

Another object is toproduce a digger unit for main connection with an auxiliary unit, as above mentioned, which is reversible so that a series of units may be arranged, longitudinally of a polygonal shaft to operatein close succession, therebyreducing the intervals between digging impulses, consequently reducing the" vibration imparted to the machine thereby, and obtaining a more efficient operation. I

Further objects and advantages will becomeapparent-from a study of the following description when taken in connection with the accompanying drawings, in which: Figure 1 is an end View of a digger of the boom type which incorporates the present invention; Figure 2 is an enlarged sectional view taken substantially on a line 22 of Figure 1;

Figure 3 is an enlarged fragmentary end view of the cutter bracket assembly shown in Figure 2;

and

Figure 4 is a side View of the bracket shown in Figure 3.

As particularly shown in Figure 1 of the drawings, the invention has been illustrated for use in connection with a boom type excavator of a convenient design. A boom is shown at In as typical of any practical arrangement adapted for elevation and depression by means operated by 40 the excavator and not shown in detail, as it does not'form a part of the present invention. The boom I0 is mounted on or carried by suitable frame structure indicated generally at [2 and forming a part of the excavating machine. Carried by the boom are a plurality of diggers 14 connected to a pair of endless chain-belts l5 driven by operating means (not shown), the chain-belts and diggers being hereinafter referred to as the main digger.

The main digger is adapted to dig a trenchof a depth corresponding to the amount of depression of the boom, and of a width corresponding to the Width of the diggers M. In order to increase the width of the trench and to vary such width, auxiliary diggers have been added to the main digger, to avoid the. necessity of providing diiferentjdiggers for each width of trench. In certain instances this has been accomplished by sets of rotary cutters on opposite sides of the boom, for supplementing the range of work of the main digger. i

It is with such'auxiliary diggersthat the present invention is more particularly concerned. Spaced from and disposed longitudinally of the boom lll' are a pair of shafts l8,one shaftbeing located adjacent each side of boom frame is. Shafts 18 are suitably rotated by gearingf(not shown) in a gear box 28 adjustable laterally of and carried by frame I9. Secured to the'frame I9 are bracket plates 2! spaced longitudinally thereof, and to which plates are adjustably secured shaft hangers 22. The hangers 2 2.carry bearingsfor journally supporting the shafts I 8, and arepro'vided with series of apertures 23 for registry with apertures in plates .21 to provide for lateral adjustment of the, shafts l8v with respect to the'boom l0. The shafts l8 are of square or other polygonal cross section'for a purpose hereinafter appearing. suitably spaced along the shaft l8 are rotary diggers 25, each comprising a pair of spiders or brackets 21 in which are positioned a pair of blades or rooters 29. Rooters 29 extend in opposite directions and have their outer extremities curved in the direction of rotation of shaft l8, to provide cutting points to enhance their digging action, as will be readily understood.

Spiders 2'! are reversible and have a base portion 32 and a blade supporting portion 33 disposed on an axis inclined at an angle of 221 degrees from the vertical with respect to the plane of the base portion, as particularly shown in Figure 3. Portion-33 is of hollow rectangular crosssection for the reception of the shank end 34 of blade 29, and has a pair of registering apertures 35 in each side Wall thereof, which apertures also register with apertures 36 in the shank portion 34 of the blade. By providing an additional aperture 36 in theshank 34, it will be noted that the blade may be adjusted longitudinally of the bracket portion 33 to vary the radius of thearc inscribed by the cutters, it being understood that a pin 36 is forced through the registering apertures 35 and 36 to secure the blade in place.

The base 32 of the spider 21 is provided with a lateral extension 31 to lend rigidity thereto and provide additional bearing surface between the bracket and shaft, the bearing surface being in the form of a V-shaped groove 40 adapted to embrace two adiacent sides of the shaft. The exl the brackets in such manner, the brackets, and

tension is apertured at 38 for the reception of bolt and nut assemblies 39 for securing the bases of oppositely disposed brackets together and in adjusted position on the shaft l8. By such arrangement it will be noted that the spiders 21 may be positioned as shown in full lines in Figure 2, and at right angles to such position. Also, by reversing the brackets so that the angle of inclination of the portions 33 are opposite to that shown in full lines, the brackets may be positioned at an angle of degrees with respect to such position. Thus, by alternately positioning thus the blades, are adapted to be located at angles of 45 degrees with respect to each' other so that each succeeding blade is effective 45' degrees ahead of or behind the next adjacent blade during rotation of the shaft.

The use of a square, or other polygonal shape, shaft I 8 has been found to have particular'utility in the present structure due to the fact that the flat side's provide positive locating means for the spiders, and the flat cooperating surfaces of the shaft and spiders militate against relative rotary movement therebetween. When round shafts, for example, are used, the blades have been secured to the shaft by dowels, which become sheared upon striking an obstruction.

By spacing the blades at the desired intervals along shaft I8, it will be seen that the digger is effective to cut additional dirt from the side of the trench in an amount equal to the path of the ends of the blades, and by spacing the cutters in accordance with the angularity of the boom, it will be noted that a continuous generally vertical cut is secured.

From the foregoing'description it will be noted that the mountingmeans for the blades or cutters permit the blades to be positively located on the shaft so that theymay be disposed in predetermined angular relation with respect to each other. It is to be further noted that the'blades may be adjusted longitudinally of the shaft as well as longitudinally of their spiders, and'that the shaft is adjustable laterally of the boom to provide a structure capable of digging trenches in a wide range of widths.

What I claim is:

1. The combination of a shaft square in crosssection, a pair of diametrically opposed brackets each having a substantially Wshaped'notch'fitting said shaft, and a cutter inclining from each bracket radially of the shaft to form an angle ofthe order of22 %g with respect to a line bi- Y secting the aforesaid V-shaped notch in each said'bracket.

' 2.An auxiliary" digger comprising a square shaft, means for rotating said shaft, a bracket 7 member secured to said shaft and having a notched baseembracing two sides of said shaft, a socket portion extending radially of the shaft at an angle of less than ninety degrees to the plane of the base of said member, whereby similar bracket members maybe reversibly mounted adjacent toeach other along said shaft with their socket portions spaced less than ninety de grees apart.

3.v The combination of a square shaft,-a brack et having a substantiallysv-shaped notch fitting said shaft, and a cutter. inclining from said bracket radially of said shaft and at an acute notch, and a cutter received in said socket portion, whereby a series of such brackets may be mounted along said shaft with the cutters radially spaced at angles of less than ninetydegrees.

- CHARLES L. GEORGE. 

